I try to keep an open mind. I do not say there is doom and gloom when there is no clear evidence. Nor do I deny the possibility of doom.

Only small-minded people insist that things are one way or the other when the truth remains unknown. It is small-minded to say "the world is ending
because of Fukushima" because there is no evidence of this yet. It is also small-minded to say "everything is OK, there is no problem."

I have to admit, this article does not inspire confidence.

Fukushima governor apologizes for deletion of data about predicted spread of radiation
FUKUSHIMA -- Gov. Yuhei Sato apologized on April 25 over prefectural government officials' deletion of data on the predicted spread of radiation
following the outbreak of the crisis at the crippled Fukushima No. 1 Nuclear Power Plant in March 2011.

At a regular news conference on April 25, Sato said, "A big problem lies in the fact that we failed to fully share the information soon after the
nuclear disaster broke out."

The NCRP2 (National Council on Radiation Protection and Measurement) estimates the cancer risk probability for a population of all ages at 0.05
per Sv.
The risk for infants
while the rate of radiation induced mental retardation is a special risk for the fetus
(an effect not observed in adults)
and in the most sensitive period, 8 - 15 weeks of gestation, is

I'm sorry, I made a mistake with the reading above. Even less: 0.06 uSv/h. I'm new to this radition reading stuff, please forgive me.

Now it's arounf 0.14 uSv/h.

The lowest reading I've gotten so far since I've been here is 0.04 uSv/h, the highest was 0.23 uSv/h. Everything else falls within this range. This
range is not excessively high, for Japan or anywhere else, I am given to understand.

I also understand there are "hot spots," floating around perhaps, so I am not sure how much a random reading of ambient air tells us. I also need a
reliable way to measure FOOD and LIQUID. It's frustraing because nobody seems to have any answers for me!

IT sats "MC" in a circle and the number is "RM-2021". The maker is Chinese. All the writing on it is in chinese.

Apparently this model is fairly common in Japan after the quake.

Getting low readings today. 0.6 uSv/h inside just now as I type this.

Okay, thank you for this information... It appears that the model that you have, only measures Electromagnetic Radiation (X-Rays, Gamma Rays), and
does not measure Alpha, Beta, or Neutron Radiation.

A Brief primer on each.....

Alpha radiation is basically the ejection of a hydrogen nucleus (2 protons, 2 neutrons)
Beta radiation is the ejection of a high energy electron
Neutron radiation is the ejection of a.... well... neutron...

The most common sources of radiation from the fukushima release are Iodine-131, and Caesium-137, and they break down as follows:

1. Releasing a 0.512 MeV Electron, and then releasing a 0.6617 MeV Gamma Ray (94.6% of the time)

2. Releasing a 1.174 MeV Electron. (5.4% of the time)

For a common source of reference: Potassium-40 (Which is naturally occurring and in your body throughout your entire life) has three possible decay
paths: en.wikipedia.org...

1. Releasing a 1.33 MeV Electron (89.28% of the time)

2. Capturing an Electron, and Releasing a 1.460 MeV gamma ray. (10.72% of the time)

3. Releasing a positron. (0.001% of the time)

Now, keep in mind, there are at any given time, 4,000 decays per second taking place in your body from Potassium-40... so this should give you a good
idea as to the normal amount of energy that your body is subject to.

So, it looks like, on average, your dosimeter isn't going to be that far off from the actual amount of radiation released from any potential
by-products of the release at Fukushima.

Originally posted by ipsedixit
Here's a suggestion for an experiment you could conduct. I'm not a scientist, so the science minded might be able to improve on this idea.

Get a coffee filter of the cone shaped variety, made out of porous paper and an atomizer (mist sprayer) of some sort to spray water at it, then take
readings with your dosimeter. Spray just enough to moisten the filter, not to soak it. You could spray every day in the same manner. If radioactive
particles are present and if you just spray enough to moisten but not soak the filter, you should begin to see an increase in your detector
readings.

Also take readings of your clothing, particularly outer garments, like coats or sweaters that you might always wear when you are outdoors. These kinds
of clothing, especially if made of wool or cotton act like filters for airborne particles.

Filters are like the human lungs or the human body. The ambient air for any given reading might be normal, but over time there could be a dangerous
build up of radioactive particles collected by any filter.

Good luck. I would love to vist Japan myself.

edit on 25-4-2012 by ipsedixit because: (no reason given)

OK, here we go. I don't have a mist sprayer, so I took a coffee filter and just sort of flicked tap water at it with my fingers until it was lightly
moistened. Then I stuck the geiger counter inside the filter so it was close to but not touching the moistened paper. The reading : 0.15 uSv/h.

Next, I wetted the filter more, so it was more soaked, and stretched it over a coffee cup. I put the geiger inside the cup so it was surrounded by the
cup and the opening was covered by the wet filter. The reading: 0.21 uSv/h.

Then, I went outside and held it really close to the silt in a gutter on the street. Its been raining recently (but not now) so the silt was damp but
not soaking. The reading: 0.12 uSv/h.

None of these are particularly high. I suppose the geiger could be broken or not synched right, to play the skeptic. I still need to verify it against
a known source of radiation. Not sure how I'm going to do that yet.

I think what I said above is true...there seem to be "hot spots" and if you aren't in one, random checks of air aren't going to do much good. I
also still don't know how good this thing is at measuring food, or anything other than random air.

Keep an open mind, don't trap yourself by being "pro doom" or "anti doom" !

Now, it seems to me, based on what you said, that my geiger only measures a limited amount of the actual radiation. However, using the proportions, I
should be able to estimate the actual uSv/h value, right? By multiplying the amount I get by some percentages, correct? Now I am far from a math whiz,
so I'm scratching my head here trying to figure out what kind of mathematical transformation I should apply to my results to get the real uSv/h
figures (including all forms of raditaion, not only the ones I can directly measure).

You wrote:

And from the isotopes that were released, they emit roughly equal amounts of the radiation that your detector can detect, and the radiation
that your detector cannot detect...

So that would suggest that I should be doubling the readings my machine picks up, right? For an estimate. So if I get a reading of 0.15 uSv/h (which
is about average of what I've been getting), it means the "real" amount is something close to 0.3 uSv/h?

None of these are particularly high. I suppose the geiger could be broken or not synched right, to play the skeptic. I still need to verify it against
a known source of radiation. Not sure how I'm going to do that yet.

Most smoke detectors contain a source of ionizing radiation. You probably have them in your apartment somewhere.

Now, it seems to me, based on what you said, that my geiger only measures a limited amount of the actual radiation. However, using the
proportions, I should be able to estimate the actual uSv/h value, right?

Yes, that is correct.

However the math is quite complex....

By multiplying the amount I get by some percentages, correct?

Roughly, yes...

So that would suggest that I should be doubling the readings my machine picks up, right?

Yes, that seems like a good rule of thumb, since Ceasium-137 and Iodine-131 release (as an aggregate) roughly equal energies of Beta particles, and
Gamma Rays, a doubling would seem appropriate.

Of corse, this would only be a WORST case scenario, as it is possible that your meter is picking up radiation that isn't from Iodine or Caesium... and
just the normal background radiation.

Thus, Doubling your readings would seem an appropriate "Margin of Error" for the average correction, given the unknowns inherent in the source of the
radiation.

So, let me see if I can calculate a "Worst Case Scenario" for you.

Ok, it seems that the *WORST* case scenario would be in the case of ALL of the radiation that you are detecting coming from Iodine-131, since:

When you want to create the, imo. useless, Test with the Coffefilter you need first
to check the Background Radiation in at least 3-4 Spots, this will be "the Noise",
but don't spend your Time for this useless Bs.!

Rainwater offer so much Radium, Barium that a reading with our cheap Instruments
is futile!

The Tapwater is free of Radiation, at least here in Setagaya!

When you want to see high Radiation you need to check your Street and the Water "Flume" (?)
(don't know if this is the right word!)
look for the Dirt inside but avoid the Metal because this will accumulate the Radiation!

Check also your Energy-Saver Bulbs, some of them give strange Readings

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